Re: [kernel-hardening] Re: [PATCH v9 1/4] syscalls: Verify address limit before returning to user-mode

[Christoph Hellwig]

On Tue, May 09, 2017 at 04:31:00PM -0700, Kees Cook wrote:
> > I don't like silent fixups.  If we want to do this, we should BUG or
> > at least WARN, not just change the addr limit.  But I'm also not
> > convinced it's indicative of an actual bug here.
> 
> Nothing should enter that function with KERNEL_DS set, right?

It might very well do.  Various drivers or the networking code mess
with the address limits for fairly broad sections of code.